The present invention is with respect to sealing or gasket fittings, and more specially to such a fitting having at least one spigot thereon.
In the prior art such gaskets have been used more specially for producing connections between loads to be supplied with fluid under pressure and parts of the system supplying such power, as for example pumps or accumulators. One field of use is in connection with fittings for joining up hydraulic or pneumatic components, more specially logical circuits running on fluid under pressure and the sensors and loads used therewith. Such components normally have a housing with a number of connection ports in one of more outer faces thereof. The ports are used for joining up with connection ducts, and for making such joints gaskets, as for example gaskets in the form of washers, are needed. Such washer-like gaskets may for example be o-rings. The are fitted in a great number of different positions on the hydraulic or pneumatic component against a sealing seat round the space within the port. To get a sealing effect the sealing washers are acted upon by some form of deforming force pushing them against the seat in sealing contact therewith so that there is no chance of any fluid being let off through the seal so formed. Normally gasket rings are placed on the outer side of the component and they have to be squeezed by a force before they give their sealing effect. The gasket rings are kept in place in ring-like grooves running round the ports for making the connections with the connection ducts. The ducts have an end flange for pushing the gasket against the sealing seat face so that the gasket ring in question is deformed.
Such a gasket system has a number of different shortcomings. On the one hand the gasket rings take up space on the outer face of the component so that the designer of such systems has to keep a certain amount of space between the ports and this is likely to make the component unnecessarily large. Having grooves or other cutouts in the component to put the gaskets in makes production relatively complex because a high quality surface then has to be produced. A key question in connection with the form of such systems is the part of the design for producing the desired gasket-deforming force. To make certain of getting a good enough sealing effect the deforming force needed has to be very much greater than the fluid pressure acting by way of the sum of the acting faces, that is to say the force having the tendency of separating the component from the duct joined to it. Every increase in the working pressure of the fluid makes a higher sealing force necessary at the gasket. When a gasket is put in place, the housing of the component has to take up the deforming forces acting on the gasket; for this reason the housing has to be designed to be so strong that it is resistant to such forces and it will not be bent. In the case of a flanged joint there is furthermore the question of fixing the flange in place. In this case it is normal to have threaded holes which have to be very large in size because of the high pulling forces that have to be taken up. For these reasons a housing with known forms of gaskets to make connection with the hydraulic or pneumatic system in the housing has to be large in its overall size and the process of manufacturing it is likely to be slow and only possible if a certain amount of material is wasted and not put to any good use.
These design troubles are more specially serious if in the field of application in question attempts are being made at standardization of such pressure fluid connections. For example in the fluidics art standardized fluid connections in the form of plug connectors have been designed. To make a connection between such plug connectors and the separate, different pressure fluid connections of the active and passive fluid components, so-called adapter blocks have to be used, which on one connection face have fluid port means in the normal standard positions and on a further face have port means that are customized to be in line with the geometry of the component. Between the two faces, the body of the adapter block has ducts in it. Plug connectors, and more specially multipole connectors, for use with such adapter blocks as so far designed have certain shortcomings, that is to say, the male and female connection parts are quite different in form so that the price of manufacturing them is high. On the other hand the male and female pieces have to have loose, moving fluid connection parts to take care of inaccuracies in manufacture and give a fully fluid-tight sealing effect. Known plug-in connectors are complex to make and to put together in other respects as well because they are made up of so many single parts. Fixing them on the adapter blocks is not possible without further fastening means as for example threaded bushes, that take up space that might otherwise be used for the connection ducts. In these respects there are the same shortcomings as with widely used gaskets that have to be squeezed to before any sealing effect is produced.